Angled inserter for drug infusion

ABSTRACT

A method of securing an infusion set to a skin surface, comprising the steps of placing a needle or cannula of the infusion set in the skin surface, and controlling a minimum bend radius of the placed needle or cannula to resist deformation and fracture thereof.

This application is a division of U.S. application Ser. No. 13/829,762,filed Mar. 14, 2013, issued as U.S. Patent. No. 10,080,839 B2 on Sep.25, 2018, the entire content of said application being incorporatedherein by reference.

FIELD OF THE INVENTION

The present invention relates generally to angled infusion sets,particularly angled intradermal infusion sets. More particularly, thepresent invention relates to angled intradermal infusion sets having aremovable inserter that prevents partial needle insertion. Moreparticularly, the present invention relates to angled intradermalinfusion sets in which a direction of user motion is different from adirection of needle insertion.

BACKGROUND OF THE INVENTION

A large number of people, including those suffering from conditions suchas diabetes use some form of infusion therapy, such as daily insulininfusions to maintain close control of their glucose levels. There aretwo principal modes of daily insulin therapy. The first mode includessyringes and insulin pens. These devices are simple to use and arerelatively low in cost, but they require a needle stick at eachinjection, typically three to four times per day. The second modeincludes infusion pump therapy, which entails the purchase of an insulinpump that lasts for about three years. The initial cost of the pump canbe significant, but from a user perspective, the overwhelming majorityof patients who have used pumps prefer to remain with pumps for the restof their lives. This is because infusion pumps, although more complexthan syringes and pens, offer the advantages of continuous infusion ofinsulin, precision dosing and programmable delivery schedules. Thisresults in closer blood glucose control and an improved feeling ofwellness.

The use of an infusion pump requires the use of a disposable component,typically referred to as an infusion set or pump set, which conveys theinsulin from a reservoir within the pump into the skin of the user. Aninfusion set typically consists of a pump connector, a length of tubing,and a hub or base from which a hollow infusion needle or cannulaextends. The hub or base has an adhesive which retains the base on theskin surface during use, which may be applied to the skin manually orwith the aid of a manual or automatic insertion device.

Currently, most insulin infusion sets deliver insulin to thesubcutaneous layers of skin using either fixed metal needles or flexibleplastic cannulas. Such infusion sets typically deliver insulin 4-10 mmbelow the skin surface. However, the upper 3 mm of skin surface, theintradermal space, facilitates better drug absorption. Unfortunately,due to the relative thinness of the intradermal layer, inserting aneedle at such depth and maintaining an infusion site over an extendedperiod of time within this narrow band is difficult.

One technique to provide intradermal injection is the Mantoux technique.As known to those skilled in the art, the Mantoux technique is typicallyused when administering tuberculosis tests. Skilled practitioners firststretch taut the selected area of skin between the thumb and forefinger,and then insert the needle slowly, bevel upward, at an angle of 5 to 15degrees to the skin surface. The practitioner then advances the needlethrough the epidermis approximately 3 mm, releases the stretched skin,and injects the medicament. However, even where intradermal delivery canbe accomplished with the standard Mantoux technique, this method ishighly variable and subject to user error.

Most insulin infusion sets typically do not provide any features toisolate the inserted needle from shock or other external forces. Sincethose infusion sets typically deliver insulin 4-10 mm below the skinsurface, shock or other external forces to the set have less effect onthe deeper inserted needle. However, where an attempt is made to targetthe upper 3 mm of skin surface, any shock or movement of the set canadversely affect needle insertion and infusion performance.

Still further, most insulin sets have inserters that can result in skinsurface “tenting” during needle insertion, where the skin surface isdeflected somewhat prior to or during needle insertion which makesprecisely targeting the upper 3 mm of skin surface difficult.

Inserted needles can be moved when a large force is exerted on theinfusion set or when the adhesive of the adhesive patch fails. A bendradius of the inserted needle can be as small as 0.005 inches, which canlead to a needle fracture after between 2-10 bend cycles. Accordingly, aneed exists for increasing the bend radius of an inserted needle toprevent needle deformation and fracture.

In general, a need exists for an infusion set that can deliver contentto the upper 3 mm of skin surface, the intradermal space, to facilitatebetter drug absorption, while maintaining a degree of comfort to theuser.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an infusion set thatcan insert a needle or cannula at an angle relative to a skin surfacevia a user motion, the angle of user motion being different from theangle of the inserted needle or cannula, to target and deliver insulinor other medicament to the upper 3 mm of skin surface.

Another object of the present invention is to provide an infusion setthat can insert a needle or cannula at an angle to duplicate the Mantouxinsertion technique and deliver insulin or other medicament to the upper3 mm of skin surface.

Another object of the present invention is to provide an infusion sethaving a skin-securing adhesive layer to secure the skin surface at theinsertion site such that the set can insert a needle or cannula with areduced risk of tenting of the skin surface and/or precisely target theintradermal depth.

Still another object of the present invention is to provide an infusionset having a cannula that substantially prevents a small bend radius ina bent inserted cannula, thereby substantially preventing cannulafracture.

In accordance with an exemplary embodiment of the present invention, aninfusion set is adapted to be secured to a skin surface includes a fixedbase member and a movable slide member. The fixed base member isconnectable to the skin surface. The movable slide member has a needleor cannula connected thereto and is movable relative to the fixed basemember. The movable slide member is movable from a first position inwhich the needle or cannula is not exposed externally of the fixed basemember to a second position in which the needle or cannula is exposedexternally of the fixed base member. The movable slide member is lockedto the fixed base member in the second position.

In accordance with another exemplary embodiment of the presentinvention, an inserter for inserting a needle or cannula of an infusionset includes a fixed inserter member and a movable inserter membermovably connected to the fixed inserter member and adapted to receivethe infusion set. The movable inserter member is movable from a firstposition to a second position to expose the needle or cannula. Themovable inserter member is locked to the fixed inserter member in thefirst position to prevent accidentally exposing the needle or cannula.

In accordance with an exemplary embodiment of the present invention, aninfusion set assembly includes an infusion set assembly adapted to besecured to a skin surface and an inserter removably connected to theinfusion set for moving the movable slide member from a first positionto a second position. The infusion set includes a fixed base memberconnectable to the skin surface, and a movable slide member having aneedle or cannula connected thereto and movable relative to the fixedbase member. The movable slide member is movable from the first positionin which the needle or cannula is not exposed externally of the fixedbase member to a second position in which the needle or cannula isexposed externally of the fixed base member.

In accordance with an exemplary embodiment of the present invention, amethod of intradermally inserting a needle or cannula of an infusion setincludes placing an infusion set having a needle or cannula on aninfusion site. An inserter connected to the infusion set is moved in afirst direction to move a slide member of the infusion set from a firstposition to a second position in which the needle or cannula is insertedin the infusion site at a non-perpendicular angle and in which theneedle is moved in a second direction different from the firstdirection.

Additional objects, advantages and salient features of exemplaryembodiments of the invention will become apparent to those skilled inthe art from the following detailed description, which, taken inconjunction with annexed drawings, discloses exemplary embodiments ofthe invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The various objects, advantages and novel features of the exemplaryembodiments of the present invention will be more readily appreciatedfrom the following detailed description when read in conjunction withthe appended drawing figures, in which:

FIG. 1 is a perspective view of an infusion set and inserter inaccordance with an exemplary embodiment of the present invention;

FIG. 2 is a cross-sectional view of the infusion set and inserter ofFIG. 1;

FIG. 3 is a perspective view of the infusion set of FIG. 1 after removalof the inserter;

FIG. 4 is a lower perspective view of the infusion set without anadhesive patch and inserter of FIG. 1 with a connector removed forclarity;

FIG. 5 is a cross-sectional view of the infusion set and inserter ofFIG. 1 prior to activation with a connector removed for clarity;

FIG. 6 is a cross-sectional view of the infusion set and inserter ofFIG. 1 prior to activation with a connector removed for clarity;

FIG. 7 is a perspective view of the infusion set and inserter duringactivation;

FIG. 8 is a cross-sectional view of the infusion set and inserter ofFIG. 1 during activation;

FIG. 9 is a bottom plan view of the infusion set and inserter of FIG. 1during activation;

FIG. 10 is a cross-sectional view of the infusion set and inserter afterinsertion of the cannula;

FIG. 11 is a bottom plan view of the infusion set and inserter of FIG.10 after insertion of the cannula;

FIG. 12 is a perspective view of the infusion set of FIG. 10 afterremoval of the inserter;

FIG. 13 is a perspective view of an infusion set prior to exposure ofthe adhesive pad;

FIG. 14 is an exploded perspective view of the infusion set of FIG. 13;

FIG. 15 is a perspective view of an inserter of FIG. 1;

FIG. 16 is a perspective view of a stationary member of the inserter ofFIG. 15;

FIG. 17 is an exploded perspective view of a movable member of theinserter of FIG. 15;

FIG. 18 is a perspective view of a slide of the infusion set of FIG. 13;

FIG. 19 is a top plan view of the slide of FIG. 18;

FIG. 20 is a front elevation view of the slide of FIG. 18;

FIG. 21 is a bottom plan view of the slide of FIG. 18;

FIG. 22 is a side elevational view of the slide of FIG. 18;

FIG. 23 is a rear elevational view of the slide of FIG. 18;

FIG. 24 is a perspective view of a hub of the infusion set of FIG. 13;

FIG. 25 is a side elevational view of the hub of FIG. 24;

FIG. 26 is a front elevational view of the hub of FIG. 24;

FIG. 27 is a rear elevational view of the hub of FIG. 24;

FIG. 28 is a top plan view of the hub of FIG. 24;

FIG. 29 is a perspective view of a movable member of the inserter ofFIG. 1;

FIG. 30 is a top plan view of the movable member of the inserter of FIG.29;

FIG. 31 is a rear elevational view of the movable member of the inserterof FIG. 29;

FIG. 32 is a cross-sectional view of the movable member of the inserterof FIG. 29;

FIG. 33 is a bottom plan view of the movable member of the inserter ofFIG. 29;

FIG. 34 is a side elevational view of the movable member of the inserterof FIG. 29;

FIG. 35 is a perspective view of a stationary member of the inserter ofFIG. 1;

FIG. 36 is a top plan view of the stationary member of the inserter ofFIG. 35;

FIG. 37 is a rear elevational view of the stationary member of theinserter of FIG. 35;

FIG. 38 is a cross-sectional view of the stationary member of theinserter of FIG. 35;

FIG. 39 is a bottom plan view of the stationary member of the inserterof FIG. 35;

FIG. 40 is a side elevational view of the stationary member of theinserter of FIG. 35;

FIG. 41 is a perspective view of a base of the inserter of FIG. 14;

FIG. 42 is a rear elevational view of the base of FIG. 41;

FIG. 43 is a bottom plan view of the base of FIG. 41;

FIG. 44 is a cross-sectional view of the base of FIG. 41;

FIG. 45 is a front elevational view of the base of FIG. 41;

FIG. 46 is a side elevational view of the base of FIG. 41;

FIG. 47 is a cross sectional view of the inserter of FIG. 1;

FIG. 48 is a bottom perspective view of the inserter of FIG. 1;

FIG. 49 is a rear perspective view of the movable member of the inserterof FIG. 1;

FIG. 50 is a bottom plan view of the movable member of FIG. 49;

FIG. 51 is a cross sectional view of the movable member of FIG. 49;

FIG. 52 is a cross sectional view of a connector tab of the movablemember engaging the infusion set slide member;

FIG. 53 is a cross-sectional view of an infusion set including a hub inaccordance with a second exemplary embodiment of the present invention;

FIG. 54 is a bottom perspective view of the hub of FIG. 53;

FIG. 55 is a cross-sectional view of the hub of FIG. 53;

FIG. 56 is a side bottom perspective view of the infusion set of FIG.53;

FIG. 57 is a cross-sectional view of the infusion set of FIG. 53;

FIG. 58 is a front bottom perspective view of the infusion set of FIG.53;

FIG. 59 is a bottom plan view of the hub of FIG. 53; and

FIG. 60 is a front elevational view of the hub of FIG. 53.

Throughout the drawings, like reference numerals will be understood torefer to like parts, components and structures.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

The exemplary embodiments of the present invention described below andshown in FIGS. 1-60 provide a means of performing an intradermal needleinsertion at an angle relative to a skin surface via a user motion inwhich the angle of user motion is different from the insertion angle ofthe needle. The insertion precisely targets the upper 3 mm of skinsurface, and delivers insulin to the intradermal layers of skin via astandard insulin pump (not shown).

For example, FIGS. 6 and 10 illustrate an infusion set assembly 1 andmotion to insert a needle 6 via a user motion in a first direction(indicated by arrow 94 in FIGS. 6 and 7) relative to a skin surface thatis different from a second direction (indicated by the angle α in FIGS.6 and 7) of the inserted needle in accordance with an exemplaryembodiment of the present invention. FIGS. 4-6 illustrate an infusionset assembly 1 in a free state before use. FIG. 10 illustrates theinfusion set assembly 1 during insertion into the skin surface at anangle relative thereto via a user motion occurring at an angle to theskin surface that is different from the needle insertion angle, inaccordance with an exemplary embodiment of the present invention.

An infusion set assembly 1, as shown in FIG. 1, includes an inserter 2and an infusion set 3. The inserter 2 includes a fixed inserter member 4and a movable inserter member 5 movably connected to the fixed insertermember 4. The movable inserter member 5 is movable from a first positionshown in FIG. 5 to a second position shown in FIG. 10. The infusion set3 includes a rigid needle 6, a hub 7, a movable slide member 8 and afixed base member 9, as shown in FIG. 14. An adhesive pad or patch 10secures the base member 9 to the skin surface. The rigid needle 6 isfixedly connected to the hub 7, which is fixedly connected to the slidemember 8. The slide member 8 moves relative to the fixed base member 9from a first position in which the needle 6 is not exposed externally ofthe infusion set 3 to a second position in which the needle 6 is exposedexternally of the infusion set 3. An opening 11 in the adhesive pad 10allows the needle 6 to pass therethrough. A connector 12 connects tubingfrom an infusion pump (not shown) to the infusion set 3.

The rigid needle 6 is preferably hollow to facilitate deliveringmedicament therethrough and is preferably made of 31 gauge stainlesssteel with a sharp beveled tip. An end port in a patient end of theneedle 6 allows the medicament to be delivered into the infusion site. Aside port can be used in addition to or instead of the end port. Anopening in the non-patient end of the needle 6 receives medicamentdelivered from the insulin pump through tubing 13.

The hub 7, as shown in FIGS. 26-30, fixedly receives the needle 6, whichcan be secured thereto in any suitable manner, such as with an adhesive.A bore 19 in the hub 7 receives the needle 6, which can be securedtherein with an adhesive. The patient end 14 of the needle 6 extendsbeyond a first end 15 of the hub 7. A septum 16 is disposed in a secondend 17 of the hub 7 to seal the hub and prevent access to the opening inthe non-patient end 18 of the needle 6. The septum 16 is preferably madeof isoprene, but any suitable material can be used. The hub 7 ispreferably made of an injection-molded plastic, although any suitablematerial can be used.

The slide member 8, as shown in FIGS. 18-23, has a front end 23 and arear end 24. An angled portion 25 of an upper surface 26 slopes upwardlyfrom the front end 23 toward the rear end 24. Preferably, the angledportion 25 has an angle of between approximately ten (10) and forty-fivedegrees (45), inclusive. More preferably, the angled portion has anangle of approximately twenty (20) degrees. An opening 27 is formed inthe angled portion 25 of the upper surface 26. A cavity 28 is formed ina lower surface 29 of the slide member 8 to receive the hub 7. Flex arms30 and 31 extend outwardly from the lower surface 29 proximal the cavity28 to facilitate securing the hub 7 in the cavity 28. Preferably, thehub 7 is secured at an angle substantially similar to the angle of theangled portion 25. Outer rails 32 and 33 extend outwardly from oppositesides of the slide member 8. Preferably, the outer rails 32 and 33 aredisposed at an angle substantially similar to that of the angled portion25. Snap arms 34 and 35 are disposed inwardly of the outer rails 32 and33. Hooks 36 and 37 extend upwardly from ends of the snap arms 34 and35. Stop arms 38 and 39 are disposed between the outer rails 32 and 33and the snap arms 34 and 35, respectively. Openings 80 and 81 in therear end 24 receive connector arms 78 and 79 (FIG. 14) to secure theconnector 12 thereto. The slide member 8 is preferably made of aninjection-molded plastic, such as PETG, but any suitable material can beused.

The base member 9, as shown in FIGS. 41-46, has a front end 40 and arear end 41. A lower surface 42 extends from the front end 40 toward therear end 41. An opening 43 in the lower surface 42 allows the needle 6to pass therethrough. Preferably, the opening 43 has a substantiallyoval shape. An upper surface 44 extends rearwardly from the front end 40and defines a cavity 45 between the supper surface 44 and the lowersurface 42 for receiving the slide member 8. Outer channels 46 and 47are formed in side walls 48 and 49 extending between the lower surface42 and the upper surface 44. A lower tab 50 extends upwardly from thelower surface 42, as shown in FIG. 44. Upper tabs 51 and 52 extenddownwardly from the upper surface 44, as shown in FIGS. 42 and 44. Innerchannels 53 and 54 are disposed between upper tabs 51 and 52 and thechannels 46 and 47. The base member 9 is preferably made of aninjection-molded plastic, such as PETG, but any suitable material can beused.

A pressure sensitive adhesive pad 10 is connected to the lower surface42 of the base member 9, as shown in FIGS. 1, 3 and 14. An adhesivebacking 55 is connected to the adhesive pad 10 to cover the adhesive padprior to use. The adhesive backing 55 has a tab element 56 to facilitateseparating the cover from the adhesive pad 10 to expose the adhesive padwhen the adhesive pad is to be secured to an infusion site. The pressuresensitive adhesive pad 10 can comprise any suitable material, such as anadhesive fabric.

The fixed inserter member 4 has an upper surface 57 with a wall 58extending downwardly therefrom, as shown in FIGS. 35-40. The uppersurface 57 and the wall 58 define a cavity 59. Preferably, the wall 58has a front wall 60 and opposing side walls 61 and 62 with a rearportion thereof being open to provide access to the cavity 59. A shelf63 disposed in the cavity 59 extends laterally between the side walls 61and 62. A flexible beam 64 extends rearwardly from the front wall 60 inthe cavity 59. The fixed inserter member 4 is preferably made of aninjection-molded plastic, such as acrylonitrile butadiene styrene (ABS),but any suitable material can be used.

The movable inserter member 5 has a rear wall 65 and opposing side walls66 and 67 extending forwardly therefrom, as shown in FIGS. 29-34. Alatching arm 68 extends forwardly from the rear wall 65 and has a tab 69extending downwardly from a free end thereof. Slots 70 and 71 extendparallel to opposite sides of the latching arm 68. A flexible member 72is preferably connected to the movable inserter member 5 by a livinghinge 73, although any suitable means for connecting the flexible membercan be used that allows deflection of the flexible member. Locking feet74 and 75 extend forwardly from side walls 66 and 67. The movableinserter member 5 is preferably made of an injection-molded plastic,such as PETG, but any suitable material can be used.

The connector 12 has flexible plastic tubing 13 connected thereto fordelivering medicament from the insulin pump (not shown) to the infusionset 3, as shown in FIG. 14. A pump connector 76 is disposed at one ofthe tubing 13 for connecting to the insulin pump. The connector 12 isdisposed at the other end of the tubing 13 for connecting to the slidemember 8 of the infusion set 3. The tubing 13 connects through a rearsurface 89 of the connector 12. A needle 77 extends forwardly from theconnector 12 to pierce the septum 16 disposed in the hub 7 when theconnector 12 is connected to the slide member 8. By piercing the hubseptum 16, the hub needle 6 is fluidly connected to the insulin pump.Snap arms 78 and 79 are received by the slide member 8 to secure theconnector 12 thereto. Moving the snap arms 78 and 79 inwardly allows theconnector 12 to be disconnected from the infusion set 3 as necessary.

A connector tab 82, as shown in FIGS. 17 and 48-51, has a base 83 andlegs 84 and 85 extending downwardly from the base 83. The legs 84 and 85of the connector tab 82 are received by the slots 70 and 71 of themovable inserter member 5 such that the base 83 is disposed above thelatching arm 68. Alternatively, the connector tab 82 can be integrallyformed with the movable inserter member 5 as a single piece.

Operation and Assembly

The exemplary embodiments comprise an adhesive secured infusion set 3and a disposable inserter 2 for performing an intradermal needleinsertion precisely targeting the upper 3 mm of skin surface. Theinfusion set 3 can be adhesively attached to a skin surface, and theinserter 2 can be used to angularly insert the needle 6 into a desiredinsertion position. The insertion position of the needle 6 is maintainedby securing the slide member 8 to the base member 9 to hold the insertedneedle 6 in position and prevent the slide member 8 and inserted needle6 from retraction once in the inserted position.

The infusion set assembly 1 can include a disposable inserter 2, asshown in FIGS. 1 and 2. The inserter 2 can also be reusable if desired.Preferably, the infusion set assembly 1 is packaged such that theinfusion set 3 is retained by the inserter 2. Alternatively, theinfusion set 3 can be packaged without the inserter 2. The needle 6 isinitially slightly recessed in the infusion set 6 to substantiallyprevent an accidental needle stick, but is visible from a bottom of theinfusion set 2, as shown in FIG. 4, so a user can visibly determinepriming of the infusion set 3 prior to adhering the infusion set 3 to aninfusion site.

The exemplary embodiments are configured to be efficient and userfriendly. The user first peels off the adhesive backing 55, revealingthe adhesive pad 10 on the lower surface 42 of the base member 9 of theinfusion set 3. The infusion set assembly 1 can then be adhered to theinfusion site with a downward pressure or application force by the user.The sliding action of the sliding base member 5 angularly inserts theneedle 6, as described in greater detail below, into the upper 3 mm ofskin surface, the intradermal space, to facilitate better drugabsorption. After the needle 6 has been inserted, the inserter 2 can beremoved and properly disposed of. The user can disconnect and reconnectthe connector 12 as desired.

Prior to activation, the infusion set slide member 8 and the movableinserter member 5 are locked in their first positions, as shown in FIGS.4-6. As noted above, the needle 6 is recessed within and visible throughthe openings 11 and 43 in the adhesive pad 10 and the base member 9,respectively, as shown in FIG. 4, thereby preventing accidental needlesticks and allowing for visible priming of the infusion set 3. The tab69 of the latching arm 68 of the movable inserter member 5 engages theshelf 63 of the fixed inserter member 4, as shown in FIGS. 5, 47 and 48,thereby preventing the movable inserter member from being separated fromthe fixed inserter member 4. Additionally, prior to activation, theflexible beam 64 of the fixed inserter member 4 engages ribs 86extending downwardly from the flexible member 72 of the movable insertermember 5, as shown in FIG. 47, thereby preventing accidental activationof the infusion set 3. Accordingly, the movable inserter member 5 isprevented from being withdrawn from the fixed inserter member 4 inaddition to being prevented from being moved into the fixed insertermember.

Additionally, the infusion set 3 is prevented from being removed fromthe inserter 2 prior to activation, as shown in FIG. 4. The locking feet74 and 75 of the movable inserter member 4 engage longitudinallyextending base members 87 and 88 (FIG. 42), thereby preventing removalof the inserter 2 from infusion set 3 prior to fully inserting theneedle 6. Inwardly extending retaining ribs 90 and 91 engage the rearsurface 89 of the connector 12 to prevent withdrawal of the infusion set3 from the inserter 2 prior to activation. Accordingly, the infusion set3 is retained by the inserter 2 prior to activation and until the needle6 is fully inserted.

The infusion set 3 is activated by moving the flexible member 72 andsqueezing the inserter 2 together, as shown in FIGS. 6 and 7. Pressingthe flexible member 72 inwardly, in a direction indicated by arrow 92,causes the flexible member 72 to rotate about the living hinge 73,thereby unlocking the inserter 2. The flexible member 72 engages andmoves the flexible beam 64 of the fixed inserter member 4 downwardly(indicated by arrow 93 in FIG. 6), thereby allowing the flexible member72 of the movable inserter member 5 to slide into the fixed insertermember 4 (indicated by arrow 94 in FIG. 7).

When the movable inserter member 5 slides into the fixed inserter member5, as shown in FIG. 8, the movable inserter member 5 pushes the rearsurface of the connector 12. As shown in FIG. 9, the inwardly extendingretaining ribs 90 and 91 of the movable inserter member 5 engage andpush the connector 12 in a forward direction. The connector 12 isconnected to the infusion set slide member 8, such that the slide member8 moves forwardly with forward movement of the connector 12. The slidemember 9 moves into the infusion set base member 9, thereby insertingthe needle 6 into the dermal layer. As shown in FIG. 8, the movableinserter member 5 is partially inserted in the fixed inserter member 4such that the needle is partially inserted. The locking feet 74 and 75of the movable inserter member 5 still engage the longitudinallyextending base member 87 and 88 of the fixed inserter member 9, as shownin FIG. 9, such that the inserter 2 cannot yet be removed from theinfusion set 3. Accordingly, the inserter 2 is prevented from beingremoved from the infusion set 3 until the needle 6 is fully inserted,thereby preventing the user from inadvertently inserting the needle 6only partially.

Additionally, the legs 84 and 85 of the connector tab 82, as shown inFIGS. 17 and 48-52, engage a rear end 24 of the slide member 8, therebyfurther facilitate forward movement of the slide member 8 with forwardmovement of the movable inserter member 5 to which the connector tab 82is connected.

As shown in FIGS. 8 and 9, the forward movement of the movable insertermember 5 causes the connector 12 to move forwardly, which causes themovement of the infusion set slide member 8 toward the fully insertedsecond position. The outer rails 32 and 33 (FIGS. 18-23) are guided bythe outer channels 46 and 47 (FIGS. 41, 42 and 44) in the infusion setfixed member 9. The outer channels 46 and 47 guide the slide member 8forwardly at an angle α (FIGS. 6 and 44) relative to the skin surface.Preferably, the angle α is between approximately ten (10) and forty-five(45) degrees, inclusive. More preferably, the angle α is approximatelytwenty (20) degrees. The needle 6 is preferably aligned with the angularinsertion direction of the slide member 8 such that the needle isinserted in the substantially axial direction of the hub 7.Alternatively, the needle 6 can be offset from the insertion angle αsuch that the insertion direction of the needle 6 includes both axialand radial components with respect to the hub 7. In such aconfiguration, the orientation angle of the needle 6 is offset from theinsertion slide angle of the slide member 8 and the hub 7.

Forward movement of the infusion set slide member 8 is stopped when thestop arms 38 and 39 abut the ends of inner channels 53 and 54 of theinfusion set base member 9. The forward movement of the connector 12 andthe movable inserter member 5 is also stopped by stopping the forwardmovement of the slide member 8. The infusion set 3 is now fullyactivated and the needle 6 is fully inserted at the angle α in theinfusion site, as shown in FIGS. 10-12. The slide member 8 and themovable inserter member 5 are now in the second position. The opening 27in the slide member 8 receives the lower tab 50 of the base member 9when the slide member 8 moves into the second position, as shown in FIG.10, thereby locking the slide member 8 to the base member 9 to preventaccidental removal of the inserted needle 6. Additionally, the hooks 36and 37 of the snap arms 34 and 35 of the slide member 8 engage the uppertabs 51 and 52 extending downwardly from the upper surface 44 of thebase member 9 to further secure the slide member 8 to the base member 9.

Now that the movable inserter member 5 has reached the second position,as shown in FIG. 11, the locking feet 74 and 75 of the movable insertermember 4 have moved past the longitudinally extending base members 87and 88. Additionally, rear portions 95 and 96 of the locking feet 74 and75 can engage rear portions 97 and 98 of the longitudinally extendingbase members 87 and 88 to further facilitate preventing removal of theinserter 2 until the needle 6 is fully inserted. The rear portions 95and 96 of the locking feet 74 and 75 are clear of rear portions 97 and98 of the longitudinally extending base members 87 and 88 when thelocking feet 74 and 75 are clear of the longitudinally extending basemembers 87 and 88. Accordingly, inserter 2 can now be removed from theinfusion set 3 by lifting the inserter upwardly with respect to theinfusion set 3 and be properly disposed of. The connector 12 can beremoved and connected to the slide member 8 as desired. The slide member8 is permanently locked to the base member 9, as described above,thereby maintaining the needle 6 in its intradermally injected positionuntil the set 3 is removed by the user.

The angular insertion of the needle 6 provides a solid anchor thatmaintains the infusion site. Typically, it is very difficult to maintainthe position of short (i.e., 1-3 mm) needles within the skin. However,by angularly inserting the needle 6, the skin itself provides a verticalretention force. Accordingly, the inserted needle 6 is secured bothvertically and horizontally. Furthermore, the angled insertion allowsfor more flexibility of needle or cannula choice for infusion byreducing the vertical height of the cannula opening. Also, because theneedle 6 is inserted at an angle, a longer needle and/or needle openingcan be used than those provided for a non-angled insertion to target thesame intradermal depth.

By first adhering the infusion set assembly 1 to the skin surface, aprecise mechanical foundation is provided which ensures that the needleangle, skin tensioning, stretching and/or flattening, and insertiondepth are consistent. Further, in doing so, tenting is also reduced oreliminated. Still further, by isolating the needle site from the pumpconnection, vibrations and movements are reduced. In addition, alow-profile is provided which further isolates the needle 6 from anyexternal forces.

By infusing into the intradermal layer of the skin, the exemplaryembodiments of the present invention offer the potential for betterabsorption of insulin when compared to subcutaneous delivery systems. Indoing so, it may be possible for the typical user to both consume lessinsulin and maintain a better medicament regime. It will be appreciatedthat multiple needles or microneedles can be used, if desired, in placeof a single needle or microneedle.

Proper alignment is accomplished by providing a solid, fixed foundationfor the user to slide the movable inserter member 5 to angularly insertthe needle 6. Such a solid, fixed foundation is provided by the adhesivelayer 10. The skin adhesive layer secures the infusion set 3 at adesired orientation, such that the needle hub 7 and needle 6 are at adesired orientation of use, and the user is substantially prevented fromholding the infusion set 3 at various angles to the insertion site.Accordingly, precise, repeatable insertions are accomplished.

Furthermore, the angle of the needle hub can be changed in this or otherexemplary embodiments of the present invention to affect the insertionangle and final placement of the needle. As shown in FIG. 6, the needle6 is aligned with the direction of travel of the hub 7. Alternatively,the needle 6 can be offset from the direction of travel of the hub 7.

Still further, in accordance with another exemplary embodiment of thepresent invention, the infusion set 3 can be activated without theinserter 2. The insertion is fully integrated into the infusion set 3such that the user does not have to carry the inserter or load theinfusion set into the inserter. The integrated system allows the usermore freedom from carrying the inserter 2. Such a system and method iseconomical, simple, and compact, and provides a system of insertion thatis integrated with the device. Therefore, a user can correctly insertthe device without inserter 2.

Second Exemplary Embodiment

A hub 107 in accordance with a second exemplary embodiment of thepresent invention is shown in FIGS. 53-60. The hub 107 substantiallyprevents a small bend radius from occurring in an inserted cannula,thereby preventing cannula fracture. Since the infusion set 103 of thesecond exemplary embodiment is substantially similar to the infusion set3 of the first exemplary embodiment shown in FIGS. 1-52, only thosefeatures of the second exemplary embodiment that are different fromthose of the first exemplary embodiment are described below. Similarreference numbers are used to describe the features of the secondexemplary embodiment, except in the 100 series, e.g., “1xx.”

The infusion set 103 includes a rigid, hollow needle 106, a hub 107, amovable slide member 108 and a fixed base member 109, as shown in FIG.53. An adhesive pad or patch 110 secures the base member 109 to the skinsurface. The rigid needle 106 is fixedly connected to the hub 107, whichis fixedly connected to the slide member 108. The slide member 108 movesrelative to the fixed base member 109 from a first position in which theneedle 106 is not exposed externally of the infusion set 103 (FIG. 2) toa second position in which the needle 106 is exposed externally of theinfusion set 103 as shown in FIG. 53. An opening 111 in the adhesive pad110 allows the needle 106 to pass therethrough. A connector 112 connectstubing 113 from an infusion pump (not shown) to the infusion set 103.

The hub 107, as shown in FIGS. 53-60, fixedly receives the needle 106,which can be secured thereto in any suitable manner, such as with anadhesive. A bore 119 in the hub 107 receives the needle 106, which canbe secured therein with an adhesive. The patient end 114 of the needle106 extends beyond a first end 115 of the hub 107. A septum 116 isdisposed in a second end 117 of the hub 107 to seal the hub and preventaccess to the opening in the non-patient end 118 of the needle 106. Theseptum 116 is preferably made of isoprene, but any suitable material canbe used. The connector 112 has a needle 177 for piercing the septum 116such that the hub needle 106 is in fluid communication with an infusionpump (not shown). The hub 107 is preferably made of an injection-moldedplastic, although any suitable material can be used.

The distal surface 191 at the first end of the hub 107 acts as apositive stop to limit the length of the needle 106 that is inserted inthe skin at the infusion site. When the patient end 114 of the needle106 is too shallow, the infusion pressure may increase to a level thatcauses a pump occlusion alarm. When the patient end 114 of the needle istoo deep, the medicament deposition can occur in the subcutaneous layerrather than the intradermal layer, thereby negatively impactingmedicament absorption. The distal surface 191 of the hub 107 acting as astop eliminates variations in insertion depth when a force is applied tothe infusion set 103. For example, when a user lies on the infusion set,the distal surface 191 of the hub 107 prevents skin from being pushedinto an opening 143 in the fixed base member 109 and pushing the needle106 further into the body.

When the adhesive of the adhesive pad 110 fails or a large force isexerted on the infusion set 103, the skin around the needle 106 can moverelative to the infusion set 103. This skin movement can cause theneedle 106 to yield, which can result in deformation or fracture of theneedle 106. An elongated slot 192 is formed in a lower surface 193 ofthe hub 107, as shown in FIGS. 54, 56, 59 and 60, that extendsrearwardly from the first end 115. Because of the elongated slot 192 inthe lower surface 193 of the hub 107, an adhesive 190, such as a gluejoint, securing the needle 106 to the hub 107 is disposed rearwardly ofthe end 195 of the slot 192 such that it is not exposed to the insertionsite, as shown in FIG. 55. Additionally, the adhesive 190 is spaced fromthe lower surface 193 of the hub 107. As shown in FIGS. 55 and 57, theadhesive 190 is disposed between the non-patient end 118 of the needle106 and the rear end 195 of the slot 192. A portion of the needle 106between the glue joint and the skin surface is free to flex, therebyfacilitating bending of the needle 106 upon movement of the hub toreduce stress in the needle. Preferably, this portion of the needle 106is approximately 0.158 inches in length.

A rounded protrusion 194 surrounds the elongated slot 192. Preferably,the protrusion 194 is a 0.020 inch radial round. Accordingly, when theneedle 106 is bent in any direction, the needle 106 bends around therounded protrusion 194, thereby allowing more bend cycles of the needle106 before it fractures because the stress in the needle issubstantially reduced by the increased bend radius provided by therounded protrusion 194. As another example, as shown in FIG. 57, aneedle 198 is bent rearwardly around a rear portion 199 of the roundedprotrusion 194. For example, as shown in FIG. 58, a needle 196 is bentaround a side portion 197 of the rounded protrusion 194. An unbentneedle 106 is shown in FIGS. 57 and 58 as a means of comparison.Accordingly, the rounded protrusion 194 preferably provides anapproximately 0.020 inch minimum radius bend, thereby preventing needledeformation and increasing the number of bend cycles before needlefracture. The flexing portion of the needle 106 provided by the locationof the adhesive 190 facilitates bending of the needle around theprotrusion 194 when the hub 107 is displaced. The increased bendingradius substantially reduces stress in the needle 106, thereby reducingthe possibility of damage to the cannula. Although there is no roundedprotrusion for an upward bend of the inserted needle 106, the lowersurface 193 of the fixed base member 109 prevents a bend of more thanapproximately 10-15 degrees.

The remaining structure, features and operation of the infusion set 103of the second exemplary embodiment are substantially similar to those ofthe infusion set 3 of the first exemplary embodiment such that forbrevity a description thereof is omitted.

Although the previously-described embodiments relate to intradermalinfusion sets, the principles of the present invention are alsoapplicable to other types of infusion sets, such as subcutaneousinfusion sets in which the patient cannula consists of a soft plasticcatheter that is inserted with the aid of a rigid metal introducerneedle.

Although only a few exemplary embodiments of the present invention havebeen described in detail above, those skilled in the art will readilyappreciate that many modifications are possible in the exemplaryembodiments without materially departing from the novel teachings andadvantages of this invention. Accordingly, all such modifications areintended to be included within the scope of this invention as defined inthe appended claims and their equivalents.

What is claimed is:
 1. A method of securing an infusion set to a skinsurface, comprising the steps of placing a needle or cannula of theinfusion set in the skin surface; controlling a minimum bend radius ofthe placed needle or cannula to resist deformation and fracture thereof;facilitating bending of the needle or cannula by providing freedom toflex; and bending the needle or cannula around a rounded protrusion on ahub of the infusion set to control the bend radius of the needle orcannula; wherein said rounded protrusion has two opposing side portionsand an adjoining rear portion together surrounding a slot in said hub,around each of which side and rear portions said needle or cannula canbend.
 2. The method of securing an infusion set to a skin surfaceaccording to claim 1, further comprising limiting an insertion depth ofthe needle or cannula in the skin surface with a surface of the hub ofthe infusion set.
 3. The method of securing an infusion set to a skinsurface according to claim 2, wherein a planar surface in a body memberof the hub limits the insertion depth of said needle or cannula.
 4. Themethod of securing an infusion set to a skin surface according to claim1, wherein said infusion set hub comprises: a body member having a firstend and a second end; and a bore extending from said first end to saidsecond end; said needle or cannula disposed in said bore such that adistal end of said needle or cannula extends beyond said first end ofsaid body member; and said slot extending rearwardly in a lower surfaceof said body member from said first end of said body member and openinginto said bore.
 5. The method of securing an infusion set to a skinsurface according to claim 4, wherein said slot defines a plane whichintersects a longitudinal axis of said bore at an angle of less than 90degrees.
 6. The method of securing an infusion set to a skin surfaceaccording to claim 1, wherein said infusion set hub comprises: a bodymember having a first end; said needle or cannula disposed in said bodymember; and said slot extending rearwardly from said first end in alower surface of said body member, said needle or cannula being disposedin said slot.
 7. The method of securing an infusion set to a skinsurface according to claim 1, wherein: said infusion set includes afixed base member connectable to the skin surface; a movable slidemember having said needle or cannula connected thereto and movablerelative to said fixed base member, said movable slide member beingmovable from a first position in which said needle or cannula is notexposed externally of said fixed base member to a second position inwhich said needle or cannula is exposed externally of said fixed basemember; said hub fixedly connected to said movable slide member andhaving a bore and said slot extending rearwardly in a lower surface froma first end thereof, said slot extending into said bore, and said needleor cannula being received in said slot; and an inserter is removablyconnected to said infusion set for moving said movable slide member fromsaid first position to said second position.
 8. The method of securingan infusion set to a skin surface according to claim 1, wherein theneedle or cannula is capable of bending in multiple directions.